Two-stroke-cycle internal-combustion engine



March 31. 1925. 1,531,397

' M. K. RINGWALDET AL TWO-STROKE CYCLE INTERNAL COMBUSTION ENGINE Filed Feb. 9, 1921 2 Sheets-Sheet 1 14/ r ml inn 21 lr/ i hIm/l March 31, 1925.

1,531,397 M. K. RINGWALD ET AL TWO-STROKE CYCLE INTERNAL COMBUSTION ENGINE 2 Sheets-Sheet 2 Filed Feb. 9, 1921 M f a/11b" M Patented Mar. 3 1, 1925- UNITED STATE s PATENT OFFICE.

MAXIMIIC'IAN KARL RINGWALD, OF AUGSBURG, AND MAX HOLLENWEGER, O'F BONN, GERMANY, ASSIGNORS TO FIRM: MASCHINENFABRIK AUGSBURG-NUERNIBEZRG. AKTIENGESELLSCHAFT, OF AUGSBURG, GERMANY, A CORPORATION OF GERMANY.

TWO-STROKE-CYCLE INTERNAL-COMBUSTION ENGINE.

Application filed February 9, 1921. Serial No. 443,723.

To all whom it may concern:

Be it known that we, MAXIMILIAN KARL RINGWALD, a citizen of the German Republie, and a resident of'the city of Augsburg, Germany, and MAX HOLLENWEGER, a citizen of the German Republic, and a resident of the city of Bonn, Germany, have invented new and. useful Improvements in Two- Stroke-Cycle Internal-Combustion Engines, of which the following is a specification.

Our invention relates to a two stroke cycle internal combustion engine with scavenging ports and to a method for the scavenging and charging the cylinders of such engines. The purpose of the invention is to provide improved scavenging devices for engines having combustion chambersinto which the liquid fuel is introduced after closing the exhaust ports and after compressing the scavenging air. For this purpose the ports for introducing the scavenging air into the cylinder and the ports through which the burned gases escape from the cylinder are arranged in diflerent planes. The scavenging air entering through the inlet ports flows over the piston head, which is preferably hollowed out, towards the opposite side of the cylinder wall which is not pierced by exhaust ports. It flows along the cylinder wall up to the cylinder cover, pressing the burned gases which move along the opposite cylinder side in the direction of the exhaust ports leaving the cylinder through the same. The exhaust and inlet ports are piston-controlled; on the down stroke of the piston first the exhaust ports and then the inlet ports are uncovered. The mixing of air and fuel takes place inside the cylinder and consequently only air is introduced into the cylinder "through the inlet ports. The fuel is injected into the combustion chamber'after the exhaust slots have been closed and after the airin the combustion chamber of the cylinder has been comprssed- In consequence of the high temperature of the compressed air, combustiontakes place in known manner. The exhaust ports are distributed over a large portion of the circumference of the cylinder, that is to say over more than one third. The part of the cylinderwall,

to which the scavenging air current entering through the inlet slots is directed, not being perforated by exhaust ports the scavenging air flows along this side of the cylinder wall in the direction of the cylinder head. The inlet slots are also distributed over more than one third of the circumference of the cylinder. They are shaped in such manner that the several currents of air entering through them unite to one current which flows in the space between the axis of the cylinder and the portion of the cylinder wall which is free from exhaust ports. The invention is applicable to single and double acting two stroke. cycle internal combustion engines. In cylinders with piston rods passing through the combustion chamber especially on the stufling box end of double acting cylinders the 1nlet slots are arranged and shaped in such manner that the currents of .air entering through them pass by the piston rod and-unite in the space between the piston rod and that part of the cylinder-wall which is without exhaust ports and flow on along the cylinder Wall. The invention" is equally applicable to engines of the vertical and.v horizontal type. I 1

Figures 1 and 2 show a double acting engine according to the invention in vertical and horizontal section, respectively, Figures 'Figure 1" and 2 each inner end of the cylinder has special inlet slots 10; they are arranged in two lines one under the other.

The air is introduced into the cylinder by a pump 12 through pipe 11. There are two inder in such a way as to occupy more than:

one third of the entire circumference of the cylinder and arranged so that the currents of air issuing from them, indicated in the drawing by dotted lines, unite between pist'on rod 9 and the cylinder wall (on the right hand side of the drawing). The exhaust ports 13 and 14 are likewise so distributed asto occupy more than one third of thecircumference of the cylinder. The side of the cylinder wall opposite to the inlet and exhaust ports (on the right hand side of the drawing) is not pierced by ex-.

haust ports. The air inlet slots 10 are distributed in two sets on the circumference of the cylinder in such a way that part of the cylinder wall is left solid. (See Figure 2.) By this disposition the currents of the scavenging air entering through the inlet slots will pass by the piston rod 9 without being deflected.

\Ve will now proceed to describe the operation of our improved engine. On the down stroke of the piston the exhaust ports 13 and 14 are opened and the burned gases begin to escape. As the piston moves on, the inlet ports 10 are also opened and the scavenging air coming from the scavenging air pump 12 and the pipe 11 enters the cylinder. The separate currents of scavenging air flow over the piston head and unitein' the space between the axis of the cylinder and that part of the cylinder wall which is not pierced by exhaust ports as shown'in Figure 2, where upon the current" flows along this cylinder wall. The scavenging air current indicatedin the figure by dotted lines, presses the burned gases onward, which gases are flowing along the side of the cylinder wall having exhaust ports, 13 and 14 and through which they escape from the cylinder. On the back stroke of the piston the inlet ports and then the exhaust ports are closed and the air in the cylinder is compressed. Thereunon the fuel is injected through fuel valves 4 in the well known manner. At the -same time the exhaust ports 14 and the inlet ports 10 of the other cylinder end are uncovered and this cylinder end is now scavenged and charged with scavenging air in the same way.

Figures 3 and 4 show the cylinder of a two stroke cycle internal combustion engine with a slightly diiferent arrangement of the inlet slots 10. In this cylinder one set of inlet slots 10 is used in providing both the cylinder ends with scavenging air. Above and below the inlet slots are the exhaust ports 13 and 14. In all other respects the arrangement according to Figures 3 and 4 conforms to that shown in Figures 1 and 2.

It will be observed that the piston head has a concave face, and the inlet ports are 4 formed in such a way. that the incomingscavenging air entering these ports is directed against this concave face and flows across it to the imperforate wall of the cylinder. The concavity assists in deflecting the air upwardly along the wall toward the head of the cylinder. The purpose of the entire arrangement of ports is such that a complete circuit of the scavenging air is pro-;

-comprising a cylinder, a piston working therein, piston controlled exhaust ports and piston controlled inlet ports for scavenging air, said exhaust portsbeing effectively opened-before said inlet ports, and said ports extending through only a portion of the cylinder circumference, the cylinder wall opposite said inlet ports being imperforatc, I o I meansfor introducing fuel into the cylinder aftersaid exhaust ports are closed, the

inlet ports being so arranged and disposed that the incoming scavenging air strikes said imperforate wall and is directed upwardly along said wall to the cylinder head, being there deflected by the cylinder head and returned to the exhaust ports, driving the burned gases before it.

2. Two cycle internal combustion engine comprising a cylinder, 'a piston working therein, piston controlled exhaust ports and piston controlled inlet ports for scavenging air, said exhaust portsextending through only a portion. of the cylinder circumference, and being effectively opened by the movement ,of the piston before said inlet ports are opened, the cylinder wall opposite said inlet portsbeing imperforate, means for inthe cylinder head, is then deflected thereby.

and flows downwardly to the exhaust ports. drivlng the burned gases to these exhaust ports and expelling them.

3. Tvocycle internal combustion engine comprismg a cyl nder, a piston working troducing fuel into the cylinder after said 4 exhaust ports are closed, the inlet ports be therein, piston controlled exhaust ports, and piston controlled 'ifiletports for scavenging air, said inlet ports extending through more than a third of thegcircumference of said cylinder, means for introducing fuel into the cylinder after said exhaust ports are closedfsaid exhaust ports being effectively. opened before said inlet ports and extending through only a portion of the cylinder circumference, the cylinder wall opposite said inlet ports being imperforate, the inlet ports being so arranged and disposed that the incoming currents of scavenging air strike said imperforate wall whereby they are directed along that wall at one side of the cylinder axis toward the cylinder head, said current being then deflected by the cylinder head, and returned to the exhaust ports, driving the burned gases through said ports.

4. A double-acting two cycle internal combustion engine comprising a cylinder, a piston working therein, centrally disposed inlet ports inthe cylinder wall, exhaust ports on one side of said inlet ports in the direction of the cylinder axis, said ports.

being controlled by said piston means for introducing fuel into the cylinder after said exhaust ports are closed, means for sup plying scavenging air to said inlet ports, exhaust pipes in connection with said exhaust ports, said exhaust ports extending through only a portion of the cylinder circumference, the cylinder wall opposite said inlet ports being imperforate, and the inlet ports being so arranged and disposed that the incoming currents of scavenging air are directed across the face of the piston, strike the said imperforate wall, flow along that wall to the cylinder head, and are there deflected downwardly to the exhaust ports,

burned gases are expelled.

' driving the burned gases before them.

5. A double-acting two cycle internal conibustion engine comprising a cylinder, a piston working therein, centrally disposed inlet ports in the cylinder wall, exhaust ports on either side of said inlet ports in the direc-. tion of the cylinder axis, said ports being arranged in planes at right angles to said cylinder axis, and being controlled by said piston, means for introducing fuel into the cylinder after said exhaust ports are closed,

' means for supplying scavenging air to said inlet ports, exhaust pipes in connection with said exhaust ports, said exhaust ports extending through only a portion of the cylinder circumference, the cyinder wall opposite said inlet ports being imperforate, the inlet ports being so arranged and disposed that the incoming scavenging air entering through the inlet ports flows across thecyl-' inder head, strikes said imperforate wall and is directed upwardly along the cylinder wall to the cylinder head, being there deflected downwardly toward the exhaust ports expelling them.

through which the burned gases are driven by said scavengingalr.

6. Two cycle internal combustion engine strikes the wall opposite the said inlet ports and is directed therealong to the cylinder head by which it is deflected in a generally downward direction to the said exhaust ports, driving the burned gases before it and expelling them through the exhaust ports,

7. Two cycle internal combustion engine comprising a cylinder, piston working therein, pistpn controlled exhaust ports and piston controlled air inlet ports disposed in the cylinder wall in different planes in the direction of the cylinder axis, said exhaust ports lying nearer the cylinder head than said inlet'ports and extending through only a portion of the cylinder circumference, the cylinderwallopposite said inlet ports being imperforate with respect to inlet ports whereby scavenging air entering through said inlet ports is positively guided through a complete circuit of said cylinder and is delivered to said exhaust ports, said scavenging air being guided successively by the piston head, said imperforate wall, the cylinder head, and the cylinder wall containing said exhaust ports to the latter, whereby the 8. A. two cycle internal combustion engine, comprisingva cylinder, a piston working therein, exhaust ports and inlet ports for scavenging air arranged in the cylinder wall, the exhaust f ports being effectively opened'prior to the opening of the 1 nlet ports,and means for introducing fuel into the cylinder after said exhaust ports are closed,-the cylinder wall opposite said inlet ports being imperforate with respect to exhaust ports, and the said inlet ports be ng so arranged and disposed that the incom ng scavenging air is directed across thevpiston head to said imperforate wall, flows upwardly along that wall toward the cylinder head, is deflected thereby, and then flows downwardly to the exhaust ports, driving the burned gases to these exhaust ports and 9. A two cycle internal combustion en ine, comprising a cylinder, a piston wor 'ng therein, this piston having a concave head 7 surface, exhaust ports and inlet 'ports for scavenging air arranged in the cylinder wall, this wall opposite the said inlet ports being imperforate with respect toexhaust ports, and means for introducing fuel into the cylinder after said exhaust ports are closed, said inlet ports being so arranged and disposed that the incoming scavenging air is directed in a slightly downward direction and across the piston head to the said imperforate Wall, flows upwardly along that Wall toward the cylinder head and is then deflected thereby and" flows downwardly 'to the exhaust ports driving the burned gases 'tpl said exhaust ports and there expelling t em.

MAX HOLLENWEGER Witnesses as to signature of Max H01len- Weger J. FLINK, JEAN FLIERENBAUM.

MAXIMILIAN KARL RINGVALD. VVitIiesses as to signature of Maximilian Karl Ringwald:

RICHARD NAUMANN, JACOB Ornzsrx. 

